A second-half fightback from Chesterfield proved to be in vain, as a 90th minute goal from Yeovil Town captain James Bailey gave the visitors a 3-2 win at the Proact.
Goals from Olufela Olomola (3') and Otis Khan (26') handed the visitors a two-goal lead at half time, before Robbie Weir (49') and Substitute Kristian Dennis (72') scored for the home side in the second half.
The Spireites pushed for a winner, but it was Bailey who secured all three points with a header at the far post following Sam Surridge's cross from the left flank.
Caretaker manager Guy Branston made one change to his starting XI, with Gozie Ugwu replacing Jordan Flores, who dropped to the bench.
In the third minute Francois Zoko’s flick on put through Olomola on goal and he calmly slotted the ball past Chesterfield goalkeeper Joe Anyon, via the post.
Chesterfield centre-half Zak Jules was stretched off shortly afterwards, with what Branston later confirmed was a hamstring injury.
Yeovil who were the better side in the first half, had opportunities to double their lead with Khan’s effort narrowly missing the post and Zoko being denied by the crossbar with a looping header.
Chesterfield’s first chance of the game came from Louis Reed; whose 25-yard effort went wide. Minutes later Ugwu worked himself a chance, but goalkeeper Artur Krysiak was on hand to tip the ball round for a corner.
But the visitors did double their lead on the 26th minute, after Khan, skipped past the challenges of Sam Hird and Laurence Maguire to curl his effort past the helpless Anyon.
Chesterfield had a bright spell five minutes before the interval, with Andy Kellett and Ugwu both having chances blocked and Chris O’Grady’s effort evaded the crossbar.
The Spireites started the second half the better of the two sides and Weir’s early goal got the home fans back on side.
O’Grady’s low driven cross was met by the Northern Irishman, who swept the ball into the bottom corner in the 49th minute.
Dennis - who had only been on the pitch for a matter of minutes - lobbed Krysiak from 25-yards out to get Chesterfield level in the 72nd minute.
With six-minutes to go full back Matthew Briggs and Reed both hit the side netting with shots from outside the area, before Bailey met Surridge’s cross to put the Glovers 3-2 ahead, with injury time looming.
Hird nearly grabbed an equaliser with the last kick of the game after a cross from the left fell his way at the far post, but the Spireites captain could only drag his effort wide.
Chesterfield: Anyon, Hird (C), Wiseman, O’Grady (Dennis 67’), Ugwu, De Girolamo, Kellett (Flores 73’), Reed, Weir, Briggs, Jules (Maguire 7’).
Substitutes not used: Lee (gk), Dimaio, Brewster, McCourt
Yeovil Town: Krysiak, Smith, Worthington, Khan, Gray (Browne 88’), Dickson, Zoko (Surridge 75’), Bailey (C), James, Olomola (Green 67’), Nelson.
Substitutes not used: Davies, Maddison, Sowunmi, Santos.
Attendance: 3,955 – 101 visiting supporters.